Citigroup Is in Talks to Purchase
Automated Trading Desk

Citigroup Inc. is in advanced talks to buy Automated Trading Desk, an electronic trading firm, for about $700 million, according to people familiar with the matter.

The purchase of the Mount Pleasant, S.C., firm could be announced this week, though details of the deal could still change. If completed, the purchase would represent a further push by the banking giant into the trading of stocks by computerized programs rather than by...